# -*- coding:utf-8 -*-
# Author:Ami
# @Time    : 2018/11/27 21:15

class A:
    def __init__(self):
        print("A")


class B(A):
    def __init__(self):
        print("B")


class C(A):
    def __init__(self):
        print("C")


class D(B, C):
    def __init__(self):
        print("D")
